Martes pennanti


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Martes pennanti
Species Authority: (Erxleben, 1777)
Common Name(s):
English Fisher
Taxonomic Notes: Molecular phylogenetic results (e.g., Koepfli et al. 2008, attached) indicate that the Fisher should in the future be classified in a monotypic genus, Pekania Gray, 1865.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Reid, F. & Helgen, K.
Reviewer(s): Duckworth, J.W. (Small Carnivore Red List Authority) & Schipper, J. (Global Mammal Assessment Team)
This species is listed as Least Concern as although habitat loss and trapping are major threats, protective regulations and reintroductions have recovered the past decline. In addition, the species is widely distributed and occurs in many protected areas.

Geographic Range [top]

Range Description:Fishers range from Quebec, the Maritime Provinces, and New England west across boreal Canada to southeastern Alaska, south in the western mountains to Utah, Wyoming, Idaho, and California, and formerly south to Illinois, Indiana, Tennessee, and North Carolina. Large range in northern North America; extirpation from southern portion of range, due mainly to habitat loss, has been counteracted by recent natural and human-aided range expansions in the eastern U.S.; adequate population data are unavailable for much of the range, but the species currently is regarded as secure.
Canada; United States
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: Densities in preferred habitat are about one fisher per 2.6 to 7.5 km2 (Coulter, 1966; Kelly, 1977). Total population size is unknown but probably is at least in the low hundreds of thousands; for example, the harvest in North America during the 1983-1984 trapping season was about 20,000 (Novak et al. 1987), and the average in the 1960s and 1970s was about 13,000 (Strickland et al. 1982).
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: Fishers inhabit upland and lowland forests, including coniferous, mixed, and deciduous forests. They occur primarily in dense coniferous or mixed forests, including early successional forest with dense overhead cover (Thomas, 1993). They generally avoid areas with little forest cover or significant human disturbance. The fisher is adapted for climbing but is primarily terrestrial. It is a generalized predator whose major prey are small to medium-sized mammals and birds, and carrion (Powell, 1981).
Systems: Terrestrial

Threats [top]

Major Threat(s): During the 19th and early 20th centuries the fisher declined over most of its range because of excessive fur trapping and habitat destruction through logging. Aubry and Lewis (2003) state that over trapping appears to have been the primary initial cause of fisher population losses in southwestern Oregon. The high value of the skins, the ease of trapping fishers (Powell, 1993), year-round accessibility in the low to mid-elevation coniferous forests, and the lack of trapping regulations resulted in heavy trapping pressure on fishers in the late 1800s and early 1900s (Aubry and Lewis, 2003). Timber harvest can fragment fisher habitat, reduce it in size, or change the forest structure to be unsuitable for fishers. Habitat loss and fragmentation appear to be significant threats to the fisher.

Conservation Actions [top]

Conservation Actions: There are currently efforts underway to implement a conservation strategy to reintroduce the fisher into its former range along the Pacific Coast. Genetic data indicate that British Columbia would be the most appropriate source population for future translocations that may be necessary to recover populations in Washington and portions of Oregon and California (Drew et al., 2003). The species is protect in large tracts of habitat in areas well distributed throughout the range. The primary conservation measure necessary is to prevent excessive harvest.

Bibliography [top]

Aubry, K. B. and Lewis, J. C. 2003. Extirpation and reintroduction of fishers (Martes pennanti) in Oregon: Implications for their conservation in the Pacific states. Biological Conservation 114: 79-90.

Drew, R. E., Hallett, J. G., Aubry, K. B., Cullings, K. W., Koepf, S. M. and Zielinski, W. J. 2003. Conservation genetics of the fisher (Martes pennanti) based on mitochondrial DNA sequencing. Molecular Ecology 12: 51-62.

Kelly, G. M. 1977. Fisher (Martes pennanti) biology in the White Mountain National Forest and adjacent areas. University of Massachusetts.

Powell, R. 1981. Martes pennanti. Mammalian species 156: 1-6.

Powell, R. A. 1993. The Fisher: Life History, Ecology, and Behavior. University of Minnesota Press, Minneapolis, MN, USA.

Strickland, M. A. 1982. Fisher Martes pennanti. In: J. A. Chapman and G. A. Feldhamer (eds), Wild mammals of North America: biology, management, and economics, pp. 586-598. Johns Hopkins University Press, Baltimore, MD, USA.

Thomas, J. W. 1993. Viability assessments and management considerations for species associated with late-successional and old-growth forests of the Pacific Northwest. The report of the Scientific Analysis Team. USDA Forest Service, Spotted Owl EIS Team, Portland, Oregon.

Citation: Reid, F. & Helgen, K. 2008. Martes pennanti. In: The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 26 March 2015.
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